Pumps



R. LUHMANN May 24, 1966 PUMPS 4 Sheets-Sheet 1 Filed Oct. 14, 1963 R. LUHMANN May 24, 1966 PUMPS 4 Sheets-Sheet 2 Filed Oct. 14. 1963 R. LUHMANN May 24, 1966 PUMP S 4 Sheets-Sheet 5 Filed Oct. 14 1963 May 24, 1966 R. LUHMANN 3,252,421

PUMPS Filed Oct. 14. 1963 4 Sheets-Sheet 4 VIII Fig. 9 F119. I0 "'0 26 F QKQ,

United States Patent 3,252,421 PUMPS Reinhold Liihrnarm, Itzehoe-Tegelhorn, Holstein, Germany, assignor to Siemen & Hinsch m.b.H., Itzehoe, Holst, Germany, a German body corporate Filed Oct. 14, 1963, Ser. No. 315,758 Claims priority, application Germany, Get. 16, 1962, S 82,060; Sept. 3, 1963, S 87,072 11 Claims. (Cl. 103-96) This invention relates to a regenerative pump of the intermittent operating type. Generally stated, the pump of this invention includes end covers which have end walls and side Walls, a rotatable shaft being transversely disposed through the end Walls, and stationary guide discs being fixed securely between the side walls transversely of the shaft and disposed in spaced relation, axially of the shaft, to cooperate at their outer peripheries with the side walls in forming a pump housing which includes the end walls of the covers. The stationary discs are spaced along the axis of the shaft to provide a chamber for a rotatable impeller, which is fixed on the shaft by a hub, with vanes radially extending straight outwardly from the hub and having opposing side edges, normal to the discs, and provided with leading edge portions that pass over the inner surfaces of the discs at a very close distance thereto. The housing is provided with an inlet at one end for a medium to be conveyed and an outlet at the other end for said medium, with the inlet being disposed outwardly of one of the discs and the outlet being disposed outwardly of the other disc. The discs are formed near the impeller vanes with passages for the conveyed medium, a side channel for liquid delivery and an auxiliary channel for gas delivery. The disc, adjoining the inlet for the conveyed medium, may be termed a suction inlet guide disc while the other disc, adjoining the outlet, may be termed an outlet guide disc.

Unlike normally sucking and fully supplied centrifugal pumps, pumps of the kind with which this invention is concerned produce loud noises which are, unfortunately, in a frequency range particularly perceptible and annoying to the human ear. The noise is often disturbing, more particularly in pumps used for domestic water supply or for pumps working in premises where people often have to remain.

Various endeavours have been made to reduce the noise made by pumps of this kind, for instance, by appropriate hydraulic design of the flow channels in the pump or by special shaping of the profiles of the impeller vanes. Another step in the same direction is to place rubber supports below the pump and the motor and to provide resilient portions in the pump intake pipe and pump delivery pipe. Attention to the construction of the pump chambers and pump components provides some slight reduction in noise but does not obviate the noise completely. The resilient supports for the pump and motor and the resilient portions of the delivery pipe and suction pipe reduce the transmission of the noise-promoting vibrations of the pump and motor to the piping and main supports, but these steps cannot of course reduce noise originating inthe pump.

The discs have main planes, which are defined as the planes that extend, through the bodies of the disw, transverse to the axis of rotation of the shaft, near the impeller. The passages and channels lie in such planes and have boundary or limiting edges.

Detailed experiments have shown that the main factor which produces or causes noise in pumps of this kind is the design of such boundary edges as the leading edge portions of the side edges of the impeller vanes pass over or by the edges at a very close distance. When the pump is in operation, the liquid entering and leaving the impeller flows onto such edges, and wherever the boundary edges extend, in the radial region of the vanes, parallel with the leading portions of the side edges of the vanes, the entering or departing liquid flow is periodically chopped up or interrupted to produce the familiar distunbing noise. The same effect occurs with curved boundary edges if they have, in a part in the radial range of the vanes, a tangent extending parallel to the leading portions of the side edges of the vanes. Also, local differences and abrupt changes in the direction and speed of flow should be reduced considerably or else, at places Where they are due .to the nature of the operation, compensated for by a bafile rib.

According to the invention, therefore, the leading portions of the side edges of the vanes pass by those boundary edges of the inlet and outlet passages for the conveyed medium, in the two discs, and the channels and gas exit apertures in the outlet disc, which lie in the main planes of the discs at an angle of from 30 to According to another feature of the invention, the passage in the inlet disc starts and ends near the impeller hub. The start and end of the suction or inlet and/or delivery passage in the discs may be covered by a pocketlike bulge on the outer sides of the disc, that is the sides which are remote 'from the impeller.

The outlet disc is provided with a gas exit aperture having boundary edges which lie in the main plane of the disc and over which the vanes pass at an angle of from 30 to 150. The gas exit aperture is partly covered by a pocket-like bulge on that side of said disc which is remote from the impeller. A bafiie rib may be disposed behind the gas exit aperture transversely of the flow therethrough.

According to another feature of the invention, at the beginning and/or ending of channels or auxiliary channels, those boundary edges thereof which appear in cylinder section form with the plane of the outlet disc an angle of 530.

The invention will now be described by way of example with reference to the accompanying drawings, in which:

FIGURE 1 is a cross-section through a renegerative P p,

FIGURE 2 is a sectional view taken along the line 22 in FIGURE 1,

FIGURE 3 is a section taken along the line 3-3 in FIGURE 1,

FIG. 4 is a section taken along a line similar to 22 of FIG. 1, the suction aperture being differ nt from the suction aperture illustrated in FIGURE 2, 1

FIGURE 5 is a partial section taken along the line 5--5 of FIGURE 4,

FIGURE 6 is a section taken along a line similar to 3-3 of FIGURE 1, the air venting sector comprising the gas exit apertures being different from FIGURE 3,

FIGURE 7 is a cylinder section taken along the line 7--7 of FIGURE 6,

FIGURE 8 is a cylinder section taken along the line 8-8 of FIGURE 6,

FIGURE 9 is a cylinder section taken along the line 9-9 of FIGURE 6, and

FIGURE 10 is a cylinder section taken along the line 10-10 of FIGURE 6.

Referring to the drawing and initially to FIG. 1, the pump comprises a housing 27, which is defined by the pump suction cover 2 and the delivery cover 10, having end walls 2 and 10'. A shaft 1 rotatably extends through the end walls with sealing means '12 being provided. A stationary guide disc 4 which may be termed an inlet guide disc and a stationary guide disc 9 which may be termed an outlet guide disc, cooperate with the side portions 10" and 2" of the covers to form the side Wall of the pump housing. The discs are fixed in a stationary fashion and arranged transversely of the shaft and spaced axially thereof to form an impeller chamber 28. An impeller 5 is rotata'bly disposed in the chamber 28 and is provided with a hub 8 fixed on the shaft and carrying vanes 6, which project straight radially outwardly from the hub and have opposing side edges 6'. The edges have leading portions which pass over or by the inner sides or faces of the discs at a very close distance. The cover 2 is provided with an inlet 3 between the end wall 2 and the inlet disc 4 and the cover 10 is provided with an outlet 11 between the end wall 10' and the outlet disc 9, the inlet and outlet being for the conveyed medium.

The inlet disc 4 is provided with a suction passage 13, as will be described, while the outlet disc 9 is provided with an outlet passage 19 for the conveyed medium and also is formed with a side channel 18 for the passage 19, and an auxiliary channel 21 for a gas exit aperture 2-3.

FIGURE 2 illustrates one possible form according to the invention, of a suction passage 13 in the guide disc 4. The start 14 and end 15 of the suction passage 13 are extended downwards to near the hub 8 so as not to be near the vanes radially. Those boundary edges 13 of the passage 13 which are in the main plane that is, the plane which passes through the body of the disc transverse to the axis of the shaft near the inner side of the disc, of the disc '4 co-operate with the leading portion or edge of the side edges of the radially extending vanes, in the manner suggested by the invention, to form an angle on of from 30 to 150.

vFIGURE 3 is an elevational view of the inner face of the outlet disc 9, looking into the pump side channel 18. The start thereof, the end :22 of the auxiliary channel 21, the start 19a and end 1% of the liquid passage 19, and the start 24a and end 24b of the gas exit passage 23, are all away from the zone of the vanes. The boundary edges 19' of the liquid exit passage 19 and the boundary edges 23" of the gas exit passage 23 co-operate with the leading edge or portion of the side edges of the vanes to form an angle of from to The casing wall 25, which is extended at the top of the pump 2 near the outer peripheries 7 of the vanes of the impeller, provides a satisfactory hydraulic seal between the suction side and delivery side of the pump chamber.

In the variation illustrated in FIGURE 4, the start 14' and end 15' of the suction passage 13' are disposed radially near the vanes, but pockets 16, 17 are connected to the start 14' and end 15' respectively and do not run out, that is, terminate, near the vanes.

To give a clear picture of the pockets 16, 17, FIG- URE 5 is a partial section along the line 55 through the suction passage illustrated in FIGURE 4. It will be apparent that those edges which are near the vanes and which do not form an angle of from about 30 to 150 with the leading or front edges of the vanes, as the same pass by are lifted out of the main plane of the guide disc.

FIGURE 6 is another section along the line 6-6 of FIGURE 1, but the air venting channel 21 and the gas exit passage 23 are different from FIGURE 3. As can be seen in FIGURE 10, the gas exit passage 23 is covered by a pocket-like bulge on that side of the guide disc which is remote from the impeller. Also, there is a bafile rib 26 behind the gas exit passage, the gas flow direction being shown by the arrows. The start 20 of the side channel 18' and the end 22 of the auxiliary channel 21 are disposed radially outside the region of the vanes, and, in contrast to FIGURES l and 3, the impeller hub 8 does not coincide with the inner boundary at the side channel 18.

Referring to FIGURES 7 to 9, at the beginning of the side channel and at the end of the auxiliary channel the boundary edges of these channels form an angle of 30 in cylinder sections with the main plane of the control disc 9. The intersection angles at the start of the side channel have the reference 5 to [3 and the angles of cylinder sections of the auxiliary channel have the references 7 and 'y What I claim is:

1. In a regenerative pump, a rotatable shaft, a rotary impeller having a hub fixed on the shaft and having vanes extending straight outwardly radially from the hub, said vanes having opposing side edges formed with leading portions, a stationary inlet disc disposed transversely of the axis of rotation of the shaft and positioned on one side of the impeller near the adjoining side edges of the vanes, a stationary outlet disc disposed transversely of the axis of rotation of the impeller and positioned on the opposite side of the impeller near the adjoining other side edge of the vanes, said inlet disc having an inlet passage formed transversely therethrough for the conveyed medium, said outlet disc having an outlet passage formed transversely therethrough for the conveyed medium, said passages lying in the main planes of the discs, said planes being transverse to the axis of rotation of the shaft, and said passages having boundary edges extending from adjacent the hub to the outer ends of the vanes near the side edges of the vanes with the leading portions of the side edges of the vanes passing over the boundary edges of the passage at an angle of from 30 to 150.

2. The invention of claim 1 wherein said boundary edges are disposed non-parallel to the vanes.

3. The invention of claim 1 wherein said passage in the inlet disc starts and ends near the hub of the impeller.

4. The invention of claim 1 wherein the passages in the discs extend from a point inwardly of the hub to a point outwardly of the outer ends of the vanes.

5. The invention of claim 1 wherein said passage in the inlet disc has boundary edges raised out of the main plane of the disc.

6. The invention of claim 5 wherein said passage has starting and ending zones covered by a pocket-like bulge on the side of the disc remote from the impeller.

7. The invention of claim 1 wherein said outlet disc has a gas delivery channel having a gas exit aperture formed transversely through the disc, said aperture having boundary edges over which the leading portions of the side edges of vanes pass at an angle of from 30 to 150 and said aperture is partly covered by a pocket-like bulge on the side of the outer disc remote from the impeller.

8. The invention of claim 7 wherein a baffle rib is disposed behind the gas exit aperture on that side of the outlet disc remote from the impeller and is positioned transversely of the flow direction with the flow impingirfig on the bulge as it passes through the aperture.

9. The invention of claim 7 wherein said outlet disc is formed on its inner side facing the impeller with a side channel for delivery of the conveyed medium to and through the outlet passage and an auxiliary channel for gas delivery to the gas exit aperture and said leading portions of the vane side edges near the inner side of the outlet disc pass over said channels at an angle of from 30 to 150.

10. The invention of claim 9 wherein said channels start and terminate away from the impeller vanes.

11. The invention of claim 9 wherein said channels have starting and terminating portions having boundary edges which appear in cylinder sections and form with the main plane of the outlet an angle of 30.

References Cited by the Examiner UNITED STATES PATENTS 3,095,820 7/1963 Sanborn et a1 l0396 FOREIGN PATENTS 993,339 7/1951 France. 752,398 10/1952 Germany. 800,806 12/1950 Germany. 886,142 1/1962 Great Britain.

SAMUEL LEVINE, Primary Examiner.

HENRY F. RADUAZO, Examiner. 

1. IN A REGENERATIVE PUMP, A ROTATABLE SHAFT, A ROTARY IMPELLER HAVING A HUB FIXED ON THE SHAFT AND HAVING VANES EXTENDING STRAIGHT OUTWARDLY RADIALLY FROM THE HUB, SAID VANES HAVING OPPOSING SIDE EDGES FORMED WITH LEADING PORTIONS, A STATIONARY INLET DISC DISPOSED TRANSVERSELY OF THE AXIS OF ROTATION OF THE SHAFT AND POSITIONED ON ONE SIDE OF THE IMPELLER NEAR THE ADJOINING SIDE EDGES OF THE VANES, A STATIONARY OUTLET DISC DISPOSED TRANSVERSELY OF THE AXIS OF ROTATION OF THE IMPELLER AND POSITIONED ON THE OPPOSITE SIDE OF THE IMPELLER NEAR THE ADJOINING OTHER SIDE EDGE OF THE VANES, SAID INLET DISC HAVING AN INLET PASSAGE FORMED TRANSVERSELY THERETHROUGH FOR THE CONVEYED MEDIUM, SAID OUTLET DISC HAVING AN OUTLET PASSAGE FORMED TRANSVERSELY THERETHROUGH FOR THE CONVEYED MEDIUM, SAID PASSAGES LYING IN THE MAIN PLANES OF THE DISCS, SAID PLANES BEING TRANSVERSE TO THE AXIS OF ROTATION OF THE SHAFT, AND SAID PASSAGES HAVING BOUNDARY EDGES EXTENDING FROM ADJACENT THE HUB TO THE OUTER END OF THE VANES NEAR THE SIDE EDGES OF THE VANES WITH THE LEADING PORTIONS OF THE SIDE EDGES OF THE VANES PASSING OVER THE BOUNDARY EDGES OF THE PASSAGE AT AN ANGLE OF FROM 30 TO 150*. 